Here's a quick one: If a tourer is not going to do self-contained touring (with all the extra camping/cooking gear), in other words he or she will be staying at motels/hostels/b & bs etc., I'd like to suggest the following:
* Attach a front and rear rack. (My definite choice for the front rack is Old Man Mountain.)
* Use medium or small-sized front panniers. (My choice is the Ortliebs.)
* Carry a trunk on the rear rack.
* Attach a handle-bar bag.
This setup would provide all the carry-space you'd need, places to keep your valuables/more delicate items, and save you a few bucks by not purchasing rear rear panniers.
David in FL